title: Mild cognitive impairment in patients with Parkinson's disease is associated with increased cortical degeneration.
abstract: Mild cognitive impairment (MCI) can occur early in the course of Parkinson's disease (PD), and its presence increases the risk of developing dementia. Determining the cortical changes associated with MCI in PD, thus, may be useful in predicting the future development of dementia. To address this objective, 37 patients with PD, divided into 2 groups according to the presence or absence MCI (18 with and 19 without) and 16 matched controls, underwent anatomic magnetic resonance imaging. Corticometry analyses were performed to measure the changes in cortical thickness and surface area as well as their correlation with disease duration. Compared with healthy controls, the PD-MCI group exhibited increased atrophy and changes of local surface area in the bilateral occipital, left temporal, and frontal cortices; whereas the PD non-MCI group exhibited only unilateral thinning and decreased surface area in the occipital lobe and in the frontal cortex. In addition, a comparison between the PD-MCI and PD non-MCI groups revealed increased local surface area in the occipital lobe, temporal lobe, and postcentral gyrus for the cognitively impaired patients. It is noteworthy that, in the PD-MCI group, cortical thickness had a significant negative correlation with disease duration in the precentral, supramarginal, occipital, and superior temporal cortices; whereas, in the PD non-MCI group, such a correlation was absent. The findings from this study reveal that, at the same stage of PD evolution, the presence of MCI is associated with a higher level of cortical changes, suggesting that cortical degeneration is increased in patients with PD because of the presence of MCI.
authors.affiliation: Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Montréal, Quebec, Canada.
authors.forename: Alexandru
authors.initials: A
authors.lastname: Hanganu
authors.forename: Christophe
authors.initials: C
authors.lastname: Bedetti
authors.forename: Thomas
authors.initials: T
authors.lastname: Jubault
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Gagnon
authors.forename: Béatriz
authors.initials: B
authors.lastname: Mejia-Constain
authors.forename: Clotilde
authors.initials: C
authors.lastname: Degroot
authors.forename: Anne-Louise
authors.initials: AL
authors.lastname: Lafontaine
authors.forename: Sylvain
authors.initials: S
authors.lastname: Chouinard
authors.forename: Oury
authors.initials: O
authors.lastname: Monchi
mesh_terms: D000368:Aged; D002540:Cerebral Cortex / Q000473:pathology*; D060825:Cognitive Dysfunction / Q000209:etiology* / Q000473:pathology* / Q000523:psychology; D018450:Disease Progression; D005260:Female; D005625:Frontal Lobe / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000473:pathology* / Q000523:psychology; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000473:pathology* / Q000523:psychology; D013702:Temporal Lobe / Q000473:pathology
keywords: Parkinson's disease; corticometry; magnetic resonance imaging; mild cognitive impairment; neurodegeneration